Eigen::internal::householder_qr_inplace_blocked< MatrixQR, HCoeffs, MatrixQRScalar, InnerStrideIsOne > Struct Template Reference

#include <HouseholderQR.h>

List of all members.

Static Public Member Functions
static void	run (MatrixQR &mat, HCoeffs &hCoeffs, Index maxBlockSize=32, typename MatrixQR::Scalar *tempData=0)

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Detailed Description

template<typename MatrixQR, typename HCoeffs, typename MatrixQRScalar = typename MatrixQR::Scalar, bool InnerStrideIsOne = (MatrixQR::InnerStrideAtCompileTime == 1 && HCoeffs::InnerStrideAtCompileTime == 1)>
struct Eigen::internal::householder_qr_inplace_blocked< MatrixQR, HCoeffs, MatrixQRScalar, InnerStrideIsOne >

Definition at line 271 of file HouseholderQR.h.

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Member Function Documentation

template<typename MatrixQR, typename HCoeffs, typename MatrixQRScalar = typename MatrixQR::Scalar, bool InnerStrideIsOne = (MatrixQR::InnerStrideAtCompileTime == 1 && HCoeffs::InnerStrideAtCompileTime == 1)>

static void Eigen::internal::householder_qr_inplace_blocked< MatrixQR, HCoeffs, MatrixQRScalar, InnerStrideIsOne >::run	(	MatrixQR &	mat,
		HCoeffs &	hCoeffs,
		Index	maxBlockSize = 32,
		typename MatrixQR::Scalar *	tempData = 0
	)		[inline, static]

Definition at line 274 of file HouseholderQR.h.

  {
    typedef typename MatrixQR::Scalar Scalar;
    typedef Block<MatrixQR,Dynamic,Dynamic> BlockType;

    Index rows = mat.rows();
    Index cols = mat.cols();
    Index size = (std::min)(rows, cols);

    typedef Matrix<Scalar,Dynamic,1,ColMajor,MatrixQR::MaxColsAtCompileTime,1> TempType;
    TempType tempVector;
    if(tempData==0)
    {
      tempVector.resize(cols);
      tempData = tempVector.data();
    }

    Index blockSize = (std::min)(maxBlockSize,size);

    Index k = 0;
    for (k = 0; k < size; k += blockSize)
    {
      Index bs = (std::min)(size-k,blockSize);  // actual size of the block
      Index tcols = cols - k - bs;              // trailing columns
      Index brows = rows-k;                     // rows of the block

      // partition the matrix:
      //        A00 | A01 | A02
      // mat  = A10 | A11 | A12
      //        A20 | A21 | A22
      // and performs the qr dec of [A11^T A12^T]^T
      // and update [A21^T A22^T]^T using level 3 operations.
      // Finally, the algorithm continue on A22

      BlockType A11_21 = mat.block(k,k,brows,bs);
      Block<HCoeffs,Dynamic,1> hCoeffsSegment = hCoeffs.segment(k,bs);

      householder_qr_inplace_unblocked(A11_21, hCoeffsSegment, tempData);

      if(tcols)
      {
        BlockType A21_22 = mat.block(k,k+bs,brows,tcols);
        apply_block_householder_on_the_left(A21_22,A11_21,hCoeffsSegment, false); // false == backward
      }
    }
  }

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The documentation for this struct was generated from the following file:

• HouseholderQR.h